Prepare release 2.1.0

[Shettland]

PR checklist

• Updating CHANGELOG.md and setup.py for new version 2.1.0
• Make sure your code lints (black and flake8).
• If a new tamplate was added make sure:
  • Template's schema is added in templates/services.json.
  • Template's pipeline's documentation in assets/reports/md/template.md is added.
  • Results Documentation in assets/reports/results/template.md is updated.
• CHANGELOG.md is updated.
• README.md is updated (including new tool citations and authors/contributors).
• If you know a new user was added to the SFTP, make sure you added it to templates/sftp_user.json

[saramonzon]

Thanks for moving the "changes" to the template changes, now it's clearer!

Now, for the release, you need to move all the info for the versión 2.1.0dev below the hotfix (just before the 2.0.0), and remove the "dev" from the tag.

On the top of the document (just like we have now the 2.1.0dev) prepare a new blank space for the next release like 2.2.0dev with every subheader blank.

[Daniel-VM]

LGTM